Lucky ones who grew up with tamales as a staple dish could script odes to the steaming cylinders of masa. Yet few big-time professional kitchens can match the comforting texture and warm, earthen flavors you get even ordering from some roadside vendors.

Perhaps they balk at the preparation time and introduce shortcuts. Or maybe they try to outthink centuries-old recipes. Certainly Tex-Mex restaurants are guilty—although not necessarily in a bad sense—of dousing the simple dish with heavy sauces. Indeed, despite claims to more authentic south-of-the-border flair, Agave Azul plates pork tamales with four different toppings. One, a pale yellow queso, presents an easygoing, hearty bite similar to cured brick dust, if you can imagine it. Next in line, ancho chile seems rather lost, begging for help from a cilantro-edged pico de gallo side. The sour cream comes across as timid, almost to the point of bland, yet capable of ruining the savory meat. Finally the ranchera sauce dribbles across its tamale as a huskier version of chile con carne.

In essence, they've presented a flight of tamales, which should tell you something about the restaurant's aspirations. Agave Azul once occupied a beige brick strip in the wasteland along Stemmons Freeway and Frankford Road. Its new digs are more appropriately kitschy: a nicely renovated structure on a corner in old downtown Carrollton, flanked by a parking lot, an auto dealership and a message splashed on the former movie theater across the way urging passers speeding by on Interstate 35 to visit the quaint square. They still stock more than 100 premium tequila brands, but their once vaunted margaritas have tottered slightly toward Mi Cocina quality. And, getting back to their tamales, kitchen staff press with such force that the masa ends up as a tightly compact cake, lacking both grittiness and flavor.

But in defense of the restaurant, persistent crowds and waitstaff hustling to turn tables strained the kitchen on my first visit. The manager—perhaps the owner, for his demeanor suggested such—seemed annoyed we failed to hop to it when he summoned us from the bar after a 15-minute wait...although in my defense, I was trying to clear our drink tab. But he kept gesturing brusquely, so we followed, forcing the overwrought bartender to chase us down.

"He's ornery," the bartender said, nodding toward her boss.

Gotta like that—true rustic charm; but mistakes by a harried kitchen staff make the older man's gruffness seem more grating than necessary, especially when errors continued to mount. Nicely seasoned beef in the tacos al carbon succumbed to flour tortillas in need of a few moments more on the griddle. The soft, stretchy dough would have marred the chicken version too, if parched, chewy meat hadn't already accomplished enough damage. Earthbound spices lend a not entirely enticing character to seafood enchiladas and, once again, glutinous flatbread finished off the mess.

The kitchen has some problems, obviously. Their salsa verde hits hard and fast with one sour stroke. The red sauce went through several mood swings. Depending upon the occasion, it could be exceedingly dull, stoked with fresh green chile or, finally, rippling with complex flavors—ripe, burnished and fruity at the same time. Which means the kitchen also finds its footing every once in awhile. Dry, nearly tough chicken almost decked another of their entrée offerings, for instance, but an intense mole, oozing wrathful chocolate over subtle twitches of sweet-sharp vegetable, diving for cover just as a firebrand tide of chile sweeps in...damn, it's good.

I mean the mole, not the tired white meat.

Something called "favorite de papa" also relies on a neat sauce, this time tequila-spiked cream, to lull you into acceptance of dull, white-noise meat. In fact, you may wish for a spoon to scoop up more of the smooth, grassy broth—but clean utensils prove to be another stumbling block. Three times servers ignored dirty silverware while swiping away plates from the previous course. I know most of us reuse knives and forks at home, but you're paying for both meal and treatment, and there's something rather unpleasant about staring at grease-stricken utensils. In general, waitstaff manage to smile efficiently, meaning you sense a little discomfort in the act. Although just maybe they've had a run-in with the ornery one, so don't take it personally.

There are one or two other little problems to consider. For example, jalapeño stuffed with cream cheese and shrimp, then battered and deep-fried, is a singularly pointless starter. Fixed against the chile's sting and a gushing mass of sour cream, the pale shellfish disappears—wasted completely except that you can clutch its tail as a kind of handle for dipping into a bowl of Agave Azul's tart and somewhat spicy queso.

If there's one consistent note, you find it in the sauces—each of which offers something of interest. Their guacamole is creamy and cooling. Pico de gallo trips between bright bursts of surprisingly robust tomato, the sting of onion and a heavy dose of cilantro, all of which combine to rescue vegetarian quesadillas so heavily laden with mushroom the wedges reek of wet, musty soil.

Don't get me wrong. Few restaurants really pass muster when it comes to Tex-Mex and to Mexican cooking...few clean ones, anyway. Agave Azul is definitely spiffy—tile floors, tall windows (so you can gape at the wonders of Carrollton past), wall colors shaded toward aged adobe and a glassed-in bar. They dump Southwestern into just about everything. Even sides of asparagus come with a dusting of crumbled chorizo. Food service wavers somewhere between the mid- and upper reaches of the genre, at least measured to local standards, so it's well worth a visit or two. Keep in mind, however, that Dallas standards are relatively lax.

Of course, if they get a handle on flour tortilla preparation, things will pick up considerably. And they still pour those all-important tequila samplers, the tray lending an air of studious reflection, of global sophistication to what is really four or five shots of cantina juice.

Yet bartenders don't show the steady touch of yore. Line cooks clearly falter when orders fly in, fast and furious. And you can't count on servers to rise above, say, the Denny's level, although better performance is not out of the question, really. I just haven't experienced it.

At least when asked, waitstaff willingly track down new silverware to replace the gobbed set. But you have to ask.